Canine skin and soft tissue tumors - Clinical and cytohistological study

Abstract

Over the course of 17 months, non-aspiration fine needle (21-27G) cytology was performed on 213 dogs with 300 skin and soft tissue tumors. The smears were air dried and stained by the Rosenfeld method. There were 119 males (56%) and 94 females (44%), the majority of at least 6 years of age (75%). Mongrel dogs were over-represented (n=74), followed by Boxer (n=21), Poodle (n=18), German Shepard (n=15), Cocker Spaniel (n=12), and Doberman Pinscher (n= 11). In 40% of the cases (85 dogs, 117Iesions), histological evaluation was available to compare with the cytologic results. In this group, 77 specimens were benign (22 non-neoplastic and 55 neoplastic) and 40 malignant. Tumors were represented by 19%non-neoplastic lesions, 36% epithelial tumors, 30% mesenchymal tumors, 13% round cell tumors and 2%melanocytic tumors. The most frequent non-neoplastic lesions were inflammatory processes (n=9) and epidermal cysts (n=9). Lipoma (n=14) and trichoblastoma (n=14) were the most common benign neoplastic lesions. Mastcell tumor (n=14) and hemangiopericytoma (n=9) represented the most common malignant lesions. When compared to histology, the cytologic examination had 89% diagnostic sensitivity, 100%specificity, 100% positive predictive value, 96% negative predictive value and 97% efficacy.